The finite element analysis of the fretting behavior between a cylinder block and a main bearing cap is presented. The stresses, relative fretting slip, frettin g friction work parameter W and crack initiation locatio...The finite element analysis of the fretting behavior between a cylinder block and a main bearing cap is presented. The stresses, relative fretting slip, frettin g friction work parameter W and crack initiation location parameter Gon the fretting contact surface of the cylinder block are obtained and analyzed. It shows that the fretting fatigue problem of the cylinder block can be quantitat ively explained by WorG. The effects of pretightening force, friction factor and material combination of the cylinder block and the main bearing cap are studied. The computational results indicate that the fretting fatigue of the cylinder block can be allayed by increasing the elastic modulus of the cylinder block, but not by changing the other two factors.展开更多
This study is an optimized extension based on the authors’previous research on the tribo-chemical reaction under constant temperature field of two-stroke internal combustion engines(ICEs).It establishes a coupled ana...This study is an optimized extension based on the authors’previous research on the tribo-chemical reaction under constant temperature field of two-stroke internal combustion engines(ICEs).It establishes a coupled analysis model that considers the tribo-chemical reactions,dynamic contact,and interface lubrication of the piston ring-cylinder liner(PRCL)system under transient temperature conditions.In this study,for the first time,the prediction of the tribofilm thickness and its influence on the surface micro-topography(the comprehensive roughness)are coupled in the working temperature field of the PRCL system,forming an effective model framework and providing a model basis and analytical basis for subsequent research.This study findings reveal that by incorporating temperature and tribofilm into the simulation model,the average friction deviation throughout the stroke decreases from 8.92%to 0.93%when compared to experimental results.Moreover,the deviation during the combustion regime reduces from 39.56%to 7.34%.The proposed coupled model provides a valuable tool for the evaluation of lubrication performance of the PRCL system and supports the analysis software forward design in two-stroke ICEs.展开更多
以内燃机典型摩擦副缸套-活塞系统为研究对象,设计和搭建内燃机缸套-活塞系统状态监测试验台。针对传统最大熵方法分析润滑油中磨粒监测数据存在的缺点,提出改进的分数矩最大熵方法(Fractional Moment Maximum Entropy Method, FM-MEM)...以内燃机典型摩擦副缸套-活塞系统为研究对象,设计和搭建内燃机缸套-活塞系统状态监测试验台。针对传统最大熵方法分析润滑油中磨粒监测数据存在的缺点,提出改进的分数矩最大熵方法(Fractional Moment Maximum Entropy Method, FM-MEM),并结合食肉植物优化算法(Carnivorous Plant Algorithm, CPA)对关键参数进行寻优求解。对润滑油中磨粒监测数据进行阈值划分,实现内燃机健康状态评估,然后将理论与试验相结合,以在线磨粒监测为主,从润滑油磨粒、理化指标以及表面形貌3个方面对内燃机缸套-活塞系统的运行状态进行监测,分析低速工况下缸套-活塞系统各个时间段的磨损健康状态及磨粒含量变化趋势,通过内燃机整机的在线磨粒监测试验,证明该方法可实现对内燃机缸套-活塞系统的实时状态监测。展开更多
文摘The finite element analysis of the fretting behavior between a cylinder block and a main bearing cap is presented. The stresses, relative fretting slip, frettin g friction work parameter W and crack initiation location parameter Gon the fretting contact surface of the cylinder block are obtained and analyzed. It shows that the fretting fatigue problem of the cylinder block can be quantitat ively explained by WorG. The effects of pretightening force, friction factor and material combination of the cylinder block and the main bearing cap are studied. The computational results indicate that the fretting fatigue of the cylinder block can be allayed by increasing the elastic modulus of the cylinder block, but not by changing the other two factors.
基金supported by the Shandong Provincial Natural Science Foundation(No.ZR2022QE183).
文摘This study is an optimized extension based on the authors’previous research on the tribo-chemical reaction under constant temperature field of two-stroke internal combustion engines(ICEs).It establishes a coupled analysis model that considers the tribo-chemical reactions,dynamic contact,and interface lubrication of the piston ring-cylinder liner(PRCL)system under transient temperature conditions.In this study,for the first time,the prediction of the tribofilm thickness and its influence on the surface micro-topography(the comprehensive roughness)are coupled in the working temperature field of the PRCL system,forming an effective model framework and providing a model basis and analytical basis for subsequent research.This study findings reveal that by incorporating temperature and tribofilm into the simulation model,the average friction deviation throughout the stroke decreases from 8.92%to 0.93%when compared to experimental results.Moreover,the deviation during the combustion regime reduces from 39.56%to 7.34%.The proposed coupled model provides a valuable tool for the evaluation of lubrication performance of the PRCL system and supports the analysis software forward design in two-stroke ICEs.
文摘以内燃机典型摩擦副缸套-活塞系统为研究对象,设计和搭建内燃机缸套-活塞系统状态监测试验台。针对传统最大熵方法分析润滑油中磨粒监测数据存在的缺点,提出改进的分数矩最大熵方法(Fractional Moment Maximum Entropy Method, FM-MEM),并结合食肉植物优化算法(Carnivorous Plant Algorithm, CPA)对关键参数进行寻优求解。对润滑油中磨粒监测数据进行阈值划分,实现内燃机健康状态评估,然后将理论与试验相结合,以在线磨粒监测为主,从润滑油磨粒、理化指标以及表面形貌3个方面对内燃机缸套-活塞系统的运行状态进行监测,分析低速工况下缸套-活塞系统各个时间段的磨损健康状态及磨粒含量变化趋势,通过内燃机整机的在线磨粒监测试验,证明该方法可实现对内燃机缸套-活塞系统的实时状态监测。
